What fan is used in the SR6?

It is important to check your SR6 to see which fan it uses.

The SR6 uses a larger round fan B155, a 6.75" fan.  However, earlier SR6 racks used a smaller square fan, the B130, which is 4.71" fan.

The B130 can also be identified by the model number MU2B1.  This fan is currently used in portable packs.